Peripheral Arterial Disease Flashcards
List the pulse points of the body that should be palpated during a cardiac examination
- Radial
- Brachial
- carotid
- Femoral
- Popliteal
- Posterior tibial
- Dorsalis pedis
What is the main cause of chronic limb ischaeia?
Atherosclerotic disease of the arteries supplying the lower limb
What are the 2 less common causes of chronic lower limb ischaemia?
- Vasculitis
2. Buerger’s Diseases
List the 5 main risk factors associated with chronic limb ischaemia
- Male
- Age
- Smoking
- Hypercholesterolemia
- Hypertension
- Diabetes
Name the classification system used to stage chronic limb ischaemia
The Fontaine classification
Explain each stage of the Fontaine Classification
Stage I-Asymptomatic, incomplete blood vessel obstruction
Stage IIA- Mild claudication pain in limb when walking a distance of greater than 200 meters
Stage IIB- Mild claudication pain in limb when walking a distance of less than 200 meters
Stage III (critical)- Rest pain, mostly in the feet
Stage IV (critical)- Necrosis and/or gangrene of the limb
What examination findings might you notice in somebody with chronic limb ischaemia?
Ulceration, Pallor & Hair loss in the leg
Differences in temperature, capillary refill, peripheral sensation and pulses between the two legs
What is the first line investigation into chronic limb ischaemia?
Duplex scan or CTA/MRIa
What are 2 advantages and 2 disadvantages of a duplex scan?
Advantages:
- Dynamic
- No radiation or contrast
Disadvantages:
- Not useful in the abdomen
- Operator dependent, time consuming
Name the tests/investigations that can be conducted in patients with suspected chronic limb ischaemia
Tests:
- Ankle Brachial Pressure Index
- Buerger’s test
Investigations:
- Duplex scan
- CTA/MRIa
- Digital subtraction angiography
Describe how the ankle brachial pressure index corresponds to the severity of chronic limb ischaemia
Ankle pressure (mmHg) / brachial pressure (mmHg)
> 1 = no symptoms
- 95-0.5 = Intermittent claudication
- 5-0.3 = Rest pain
<0.2 = gangrene and ulceration
Describe Brueger’s Test
Elevate the legs
and look for Pallor & Buerger’s Angle (< 20 degrees severe ischaemia)
THEN
Hang feet over edge of bed and look for: Slow to regain colour & a dark red colour (hyperaemic sunset foot)
What happens during Digital subtraction angiography?
Stents are fitted in the damaged vessel
How should patients with chronic limb ischaemia be managed?
in the same way as those with coronary artery disease!
- Antiplatelets & statins
- Target BP. <140/85
- Smoking cessation, diabetic control and increased exercise
- Open surgery (bypass and/or endarterectomy)
What are the risk factors associated with open surgical management of a patient with chronic limb ischaemia?
Bleeding, wound infection, pain, scar, DVT, PE, MI, CVA, LRTI, death, damage to nearby vein, artery, nerve, distal emboli, graft failure
What is the re-intervention rate of patients with chronic limb ischaemia?
18.3-38.8%
What is the name of the trial which looked at chronic limb ischaemia patient outcomes between angioplasty or surgery?
The BASIL trial
What were the main findings of the BASIL trial?
If short-term results are what matter angioplasty is the likely preferred strategy.
However, in patients with suitable anatomy, vein availability and a reasonable life expectancy, surgery may be better for greater long-term durability.
What is the difference between chronic and acute limb ischamia?
Chronic= caused usually by an atheroma in the peripheral arteries and develops over a long perid of time
Acute= Caused by an embolus or a thrombus (NOT A DVT!) and is a medical emergency
What % of acute limb ischaemia cases are caused by A) Embolus and B) Thrombus
A) 30%
B) 60%
What are some of the common causes of acute limb ischaemia
Arterial embolus such as MI, AF or proximal atherosclerosis
Thrombus from a previously diseased artery
Trauma
Dissection
Acute aneurism
What are the clinical features of acute limb ischaemia? (The 6 P’s)
- Pain
- Pallor
- Pulse Deficit
- Paraesthesia
- Paresis/Paralysis
- Poikilothermia (cold)
Compare to contralateral limb
When does acute limb ischaemia become irreversible?
After 6-8 hours (this is when it is then classed as compartment syndrome)
What are the features of compartment syndrome?
- Inflammation
- Oedema
- venous obstruction
- Rise in creatinine kinase
- Risk of renal failure (myoglobulinaemia)
How is acute limb ischaemia managed if it has been caused by an embolus and the limb is still salvageable?
Embolectomy
How is acute limb ischaemia managed if it has been caused by an thrombus and the limb is still salvageable?
Endovascular mechanical thrombectomy or thrombolysis
How should a patient with acute limb ischaemia be managed if the limb cannot be salvaged?
If possible, amputate, if not palliate
What % of diabetic patients will develop a foot ulcer in their lifetime?
25%
What % of diabetic foot ulcers become infected?
50%
What % of diabetic foot ulcers result in amputation?
20%
What 6 factors contribute to the formation of a diabetic foot ulcer?
- microvascular peripheral artery disease
- Peripheral neuropathy
- Mechanical imbalance
- Foot deformity
- Minor trauma
- Susceptibility to infection
What measures can be taken to avoid the development of a diabetic foot ulcer?
- Always wear shoes
- Check the fit of footwear
- Check pressure points and the underside of the foot regularly
- Take care of skin breaches on the foot
- Control blood sugars!!
How is a diabetic foot ulcer managed?
- Prevention
- Careful wound management
- Consider systemic antibiotics if there is a possiblity of infection
- Investigate for osteomyelitis, gas gangrene, necrotizing fasciitis
- Revascularise distal disease
- Amputation if appropriate
- Dressings
- Debridement
- Negative pressure wound closure
- Skin grafts
